Folded oil well mast structure



Jan. 3, 1967 H. J. WOOLSLAYER ETAL 3,295,270

FOLDED OIL WELL MAST STRUCTURE 5 Sheets-Sheet 1 Filed Nov. 5, 1964//VVE/V7'0R5. HOMER J. WOOLSLAYER CECIL Jf/Vkl/V-S ATTORNEYS.

3, 1967 H. J WOOLSLAYER ETAL 3,295,270

- FOLDED OIL WELL MAST STRUCTURE 5 Sheets-$heet 2 Filed Nov. 5, 1964IIAL u M T M Arrow/5V5.

Jan. 3, 1967 H- J. WOOLSLAYER ETAL FOLDED OIL WELL MAST STRUCTURE FiledNov. 5, 1964 5 Sheets-Sheet :5

wumro/Qs i) HOMER J. WOOLSLAYER cam JEAN/NS mgwawwm ATTOR ilnitd ratesatent 3,295,270 FOLDED 01L WELL MAST STRUCTURE Homer .l. Woolslayer andCecil Jenkins, Tulsa, Dltla, assignors to Lee C. Moore Corporation,Pittsburgh, Pa, a corporation of Pennsylvania Filed Nov. 5, 1964, Ser.No. 469,039 11 Claims. (Eli. 52-417) This invention relates to oil wellmasts that can be folded for transportation from one location toanother.

Oil well drilling masts that can be swung upward from the ground toupright drilling position are well known, but generally such masts haveto be controlled in their movement by a snub line connected with a winchtruck. When it is desired to carry such a mast on a barge, the limitedspace on the barge deck precludes the use of a winch truck or the like.Folding masts, which can be raised and lowered in a limited area withouta snub line, also are known, but in the past they have been rathercomplicated in construction and operation. Nevertheless, a folding mastis desirable for a barge so that the mast can be lowered, without beingdismantled, while the barge is under tow from one location to another.

It is among the objects of this invention to provide a folded maststructure which is simple in construction and operation, which can beerected and folded by its own power plant connected with the travellingblock, and which requires no snub lines or the like to aid in theerection and folding of the mast.

In accordance with this invention, a reclining lower mast section has afoot pivotally connected to a base that may be mounted on a barge. Thislower section extends forward over the base from the foot. Recliningabove the lower section is an upper mast section that has a head at theback of the base. The front end of the lower side of the upper sectionis hinged to the front end of the upper side of the lower section. Theupper side of the upper section extends forward beyond the hinge tooverhang the underlying lower section. Pivoted legs, which are inclinedlengthwise of the base, have upper ends pivoted to the overhangingportion of the upper section. The lower ends of the legs are pivotallyconnected to the base between the locations of the ends of the reclininglower section. Means are provided for swinging one of the mast sectionsupwardly. The lower ends of the legs are in a position to cause the legsto swing the other mast section upwardly relative to the first sectionuntil both sections are erect with the upper section resting on top ofthe lower section. Means may also be provided for then changing theposition of the lower ends of the pivoted legs relative to the basesufiiciently to allow the two erect mast sections to swing forward undergravity from a position where the center of gravity of the upper sectionis behind the hinging means to drilling position where said center ofgravity is in front of the hinging means.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which FIG. 1 is a plan view of the foldedmast;

FIG. 2 is a side view thereof;

FIG. 3 is a fragmentary side view of the erected mast;

FIG. 4 is a rear view thereof;

FIG. 5 is a fragmentary front view of the erected mast;

FIG. 6 is a line drawing showing the mast in erect drilling position;

FIG. 7 is a fragmentary side view of the front portion of the base; and

FIG. 8 is a vertical section taken on the line VIllVlIl of FIG. 7.

Referring to FIGS. 1 and 6 of the drawings, a base it of the skid basetype has drawworks 2 mounted on it near its rear end. Such a base isadapted to be rigidly mounted on a trailer or on a barge (not shown). Apair of rear shoes 3 are mounted on the base at opposite sides of thedrawworks, and the bifurcated foot of an upright mast is pivotallyconnected to these shoes. The mast is divided into two sections; a lowersection 4 supporting an upper section 5. The lower section leans forwardslightly. The two mast sections meet along an inclined plane extendingupwardly and rearwardly from the lower end of the front side of theupper section. end of this plane the back sides of the two sections arehinged together on a horizontal axis by suitable hinge brackets 6. Themast is supported in upright drilling position by a pair of legs 7 thatare pivotally connected at 8 to the lower end of the front of the uppersection. The legs extend downward and forward from the mast, with theirlower end portions pinned to brackets 9 mounted on the front end of thebase. The head of the mast supports the usual crown block 11 (FIG. 6),from which a travelling block 12 is suspended inside the mast by adrilling line 13 that also extends from the crown block down the insideof the mast to the drawworks. This line passes in front of a horizontalroller 14 journaled in the back of the mast close to its hinge.

The mast will now be described in its folded position, as shown in FIGS.1 and 2, for a better understanding of its construction and operation.In this position the lower section 4 of the mast is reclining andextends forward over the base from rear shoes 3 and it may projectbeyond the front end of the base. It can rest on a temporary support 16on the base. The upper mast section reclines above the lower section andextends rearwardly from the hinge 6 and over a removable support 17,thereby locating the head of the mast at the back of the base. The upperside of the reclining upper section extends forward beyond the hinge tooverhang the underlying lower section. The legs 7 are inclineddownwardly and rearwardly from their connection to the upper section tothe base at points between the ends of the reclining lower section.

For a purpose that will be explained presently, it is preferred thatwhile the mast is folded the pivoted legs not be connected to brackets9. Instead, the lower ends of the legs are connected to means by whichtheir position can be changed in order to lower the legs relative to thebase. Preferably, therefore, the lower ends of the legs are pivotallyconnected by pins 13 to the upper ends of vertical triangular frontshoes 19, the lower ends of which are pivotally mounted on pins 20secured in the lower part of the base behind brackets 9. The backs ofthe shoes are pivotally connected to piston rods 21 ex tendingrearwardly into hydraulic cylinders 22, the rear ends of which arepivoted in the base at 23, as best shown in FIG. 7. It will be seen thatthe reclining legs extend from shoes 19 forward over the brackets.

The location of pivot pins 13 is such that when either mast section isswung upwardly, such as by lines connected to the upper section or by ahydraulic ram beneath the lower section, the legs 7 will swing the othermast section upwardly relative to the first section. Thus, the head ofthe mast will swing upward and forward as hinge 6 swings upward andbackward. These movements will continue until the upper section is erectand rests on the lower section, to which it then can be bolted orclamped in any suitable manner. About the simplest way to erect the mastis by means of the drawworks and travelling block and the line 13connecting them. In such a case, the hook 125 of the travelling block isconnected to a sling 2 5 that extends forward over the front end of theupper side of the reclining upper section of the mast, such as oververtical sheaves 27 journaled in the front end of At the upper a theupper section. From these sheaves the sling, formed from a cable doubledon itself, extends downwardly to rigid means projecting forward from thereclining lower section. Preferably, such means is in the form of aframework 28 that is rigidly connected to the front end of the reclininglower section and that includes a pair of laterally spaced channelmembers 29, which extend forward from the lower section and then curveupwardly. The channel members are open at the bottom. The sling extendsback through these channel members and has its opposite ends secured tothe lower section, such as to brackets 30 attached to the upper part ofthe lower section. When the drawworks is operated to reel in line 13,the pressure of the sling against sheaves 27 swings that end of theupper section down around hinge 6, but that motion is restrained andcontrolled by legs 7 which simultaneously compel the adjoining end ofthe lower section to swing upward. Therefore, the upper end of the lowersection swings backward at the same time as the upper end of the uppersection swings forward, until the upper section is erect and rests ontop of the lower section. The framework 28 is narrow enough to swinginto the upper section of the erect mast.

It will be seen in FIG. 6 that if the mast were raised directly to thesolid line drilling position in this manner, the center of gravity ofits upper section would lie in front of hinge 6. In such a case the mastcould not be folded again until its upper section had been swungbackward on the hinge far enough to start swinging down by gravity, butsuch breaking of the toggle formed by the mast would require a lineconnected to the top of the mast, and means located some distance behindthe mast for pulling the line. It is to avoid such a line and pullingmeans that is another feature of this invention. This is the reason forhaving the lower ends of legs 7 connected to shoes 19 instead of tobrackets 9 during raising of the mast. Consequently, shoes 19 duringerection are maintained in their full line position shown in FIGS. 7 and2 so that by the time the erect upper mast section is seated on theerect lower section, the pivoted legs will have required the entire mastto be swung backward past its drilling position far enough for thecenter of gravity of the upper section to be located behind the masthinge in the upper dotted line position in FIG 6, but preferably not farenough for the center of gravity of the mast as a whole to be behindrear shoes 3. After the two erect mast sections have been clampedtogether in this position, fluid pressure is delivered to the rear endsof cylinders 22 to cause the shoes 19 to be swung forward and down, totheir dotted line positions shown in FIGS. 7 and 3, thereby loweringlegs 7 and permitting the mast to swing or settle forward into uprightdrilling position, wherein the center of gravity of the upper sectionwill be well in front of the mast hinge. Legs 7 then are pinned tobrackets 9.

To fold the mast again, sling 26 is connected to the travelling blockand put under tension, the gin pole legs then are unpinned from brackets9, then the pivoted front shoes 19 are swung backward and up by thehydraulic cylinders to swing the mast back to its rear erect positionwhere the center of gravity of the upper section again will be behindhinge 6, the upper and lower sections of the mast then are disconnectedfrom each other in front of the hinge, and then the upper section 5 isallowed to swing backward and down by gravity but under the control ofthe travelling block and sling and pivoted legs. Simultaneouslytherewith, the lower mast section will swing forward and down as thetravelling block is lowered in the upper section, with the result thatthe mast will fold itself over the base.

If desired, the front shoes 19 could be so designed and their movementmade such that after the mast has been folded they could be movedforward into a position where they could be left while the mast is swungup directly to drilling position without first going past that point andhaving to be returned to it. The folding procedure would be the same asbefore, however; the front shoes would have to be moved to their rearposition to cause the pivot-ed legs to swing the mast backward a fewdegrees before the upper section could start to fold under the influenceof gravity. In either case, no outside lines or winch trucks arerequired for unfolding or folding the mast.

According to the provisions of the patent statutes, we have explainedthe principle of our invention and have illustrated and described whatwe now consider to represent its best embodiment. However, we desire tohave it understood that, within the scope of the appended claims, theinvention may be practiced otherwise than as specifically illustratedand described.

We claim:

1. A folded mast structure comprising a base having front and rear ends,a reclining lower mast section having a foot pivotally connected to saidbase, said section extending forward over the base from said foot, anupper mast section reclining above the lower section and having a headat the back of the base, means hinging the front end of the lower sideof the upper section to the front end of the upper side of the lowersection, the upper side of the upper section extending forward beyondsaid hinging means to overhang the underlying lower section, rigid,unitary legs inclined lengthwise of the base and having upper endspivoted to said overhang, shoes pivotally connecting the lower ends ofthe legs to said base between the locations of the ends of the reclininglower section, and means for swinging one of the mast sections upwardly,the lower ends of the legs being held down by said shoes in a positionto cause the legs to swing the other mast section upwardly relative tosaid one section until both sections are erect with the upper sectionresting on top of the lower section.

2. A folding mast structure according to claim 1, in which said swingingmeans include rigid means projecting forward from the reclining lowersection, a sling connected with said rigid means and extending up overthe front end of the upper side of the reclining upper section and thenrearwardly down into that section, a travelling block in the uppersection connected to the sling, and means for pulling the block towardthe head of the mast.

3. A folding mast structure according to claim 2, in which said rigidmeans includes a pair of laterally spaced downwardly and forwardlyopening channel members, and said sling is a cable doubled on itself andextending through said channel members with its opposite ends secured tothe upper part of the reclining lower section, said channel membersextending up into said upper section when the mast is erect.

4. A folding mast structure according to claim 2, in which said pullingmeans include drawworks mounted on said base adjacent said foot, a crownblock mounted on said head, a line-supporting member mounted near saidhinging means, and a line connected with the travelling block andextending rearwardly therefrom around said crown block and then forwardand around said supporting member and then rearwardly to connection withthe draw works.

5. A folding mast structure according to claim 2, including a pair oflaterally spaced vertical sheaves journalled in the front end of thereclining upper section near its upper side, and said sling being acable doubled on itself and extending over said sheaves and having itsopposite ends secured to said lower section.

6. A folded mast structure comprising a base having front and rear ends,a reclining lower mast section having a foot pivotally connected to saidbase, said section extending forward over the base from said foot, anupper mast section reclining above the lower section and having a headat the back of the base, means hinging the front end of the lower sideof the upper section to the front end of the upper side of the lowersection, the upper side of the upper section extending forward beyondsaid hing- .5 ing means to overhang the underlying lower section, legsinclined lenghtwise of the base and having upper ends pivoted to saidoverhang, means pivotally connecting the lower ends of the legs to saidbase between the locations of the ends of the reclining lower section,means for swinging one of the mast sections upwardly, the lower ends ofthe legs being in a position to cause the legs to swing the other mastsection upwardly relative to said one mast section until both sectionsare erect with the upper section resting on top of the lower section ina position where the center of gravity of the upper section is behindsaid hinging means, and means for then changing the posi tion of saidleg-connecting means relative to the base sufficiently to allow the twoerect mast sections to swing forward together to upright drillingposition with said center of gravity in front of the hinging means.

7. A folding mast structure according to claim 6, in which saidleg-supporting means are shoes pivotally connected to said legs andbase, said structure including means for swinging the shoes on the baseto a position in which the legs will allow the two erect mast sectionsto swing forward to said drilling position.

8. A folding mast structure according to claim 7, in which the bottomsof said shoes are pivotally connected to the base, the tops of the shoesare pivotally connected to the legs, and said shoe-swinging means swingthe shoes forward and down to move the adjoining ends of said legsforward and down to a lower position.

9. A folding mast structure according to claim 7, in which saidshoe-swinging means are fluid pressure operated rams behind the shoes.

10. A folding mast structure according to claim 7, including means fordetachably connecting said legs to the base in their forward position.

11. A folded mast structure comprising a base having front and rearends, a reclining lower mast section having a foot pivotally connectedto said base, said section extending forward over the base from saidfoot, an upper mast section reclining above the lower section and havinga head at the back of the base, means hinging the front end of the lowerside of the upper section to the front end of the upper side of thelower section, the upper side of the upper section extending forwardbeyond said hinging means to overhang the underlying lower section, legsinclined lengthwise of the base and having upper ends pivoted to saidoverhang, shoes pivotally connected to the lower ends of said legs andto said base between the locations of the ends of the reclining lowersection, rigid means projecting forward from the reclining lowersection, a sling connected with said rigid means and extending up overthe front end of the upper side of the reclining upper section and thenrearwardly down into that section, a travelling block in the uppersection connected to the sling, means for pulling the block toward thehead of the mast to swing the upper section upwardly, said shoes beingin a position to cause the legs to swing the lower section upward onsaid foot until both mast sections are erect with the upper sectionresting on top of the lower section in a position where the center ofgravity of the upper section is behind said hinging means, and means forswinging said shoes forward on the base to a position in which the legswill allow the two erect mast sections to swing forward together toupright drilling position with said center of gravity in front of thehinging; means.

References Cited by the Examiner UNITED STATES PATENTS 2,573,528 10/1951 Woolslayer et al. 52117 X 2,683,584 7/1954 Selberg 52116 X3,033,527 5/1962 Wilson 52-116 X 3,181,658 5/1965 Bender 52116 FOREIGNPATENTS 942,619 5/ 1956 Germany. 738,198 10/ 1955 Great Britain. 65,4186/ 1913 Switzerland.

FRANK L. ABBOTT, Primary Examiner.

R. S. VERMUT, Assistant Examiner.

1. A FOLDED MAST STRUCTURE COMPRISING A BASE HAVING FRONT AND REAR ENDS,A RECLINING LOWER MAST SECTION HAVING A FOOT PIVOTALLY CONNECTED TO SAIDBASE, SAID SECTION EXTENDING FORWARD OVER THE BASE FROM SAID FOOT, ANUPPER MAST SECTION RECLINING ABOVE THE LOWER SECTION AND HAVING A HEADAT THE BACK OF THE BASE, MEANS HINGING THE FRONT END OF THE LOWER SIDEOF THE UPPER SECTION TO THE FRONT END OF THE UPPER SIDE OF THE LOWERSECTION, THE UPPER SIDE OF THE UPPER SECTION EXTENDING FORWARD BEYONDSAID HINGING MEANS TO OVERHANG THE UNDERLYING LOWER SECTION, RIGID,UNITARY LEGS INCLINED LENGTHWISE OF THE BASE AND HAVING UPPER ENDSPIVOTED TO SAID OVERHANG, SHOES PIVOTALLY CONNECTING THE LOWER ENDS OFTHE LEGS TO SAID BASE BETWEEN THE LOCATIONS OF THE ENDS OF THE RECLININGLOWER SETION, AND MEANS FOR SWINGING ONE OF THE MAST SECTIONS UPWARDLY,THE LOWER ENDS OF THE LEGS BEING HELD DOWN BY SAID SHOES IN A POSITIONTO CAUSE THE LEGS TO SWING THE OTHER MAST SECTION UPWARDLY RELATIVE TOSAID ONE SECTION UNTIL BOTH SECTIONS ARE ERECT WITH THE UPPER SECTIONRESTING ON TOP OF THE LOWER SECTION.